A biopolymer is a polymer suitable for introduction into a living organism, e.g., a human. The biopolymer is usually non-toxic and bioabsorbable when introduced into the living organism, and any degradation products of the biopolymer are also non-toxic to the organism. The biopolymer can be formed into biocompatible constructs that include, for example, biopolymer foams, e.g., single or double density foams, and/or biopolymer fibers. The construct can also include extracellular matrix particulates.
Biopolymers, such as sponges or foams are very useful in vitro to provide model systems for research, or in vivo as hemostatic agents, scaffolds or as prostheses and implants to replace damaged or diseased tissues. In both in vivo and in vitro applications, the foams can be seeded with various cell types, allowing in vitro study of cell functions in three dimensions, and promoting in vivo remodeling and integration of the implant or prosthesis. Often a biopolymer construct that includes a biopolymer foam is prepared in vitro, such as by seeding the foam with cells and culturing the growth and differentiation of these cells, prior to use in vivo.
Many different foam-based constructs are possible, and often it is desirable that the shape of a foam construct resemble the organ or tissue the foam is to model or replace. To create a foam construct of a desired shape, a biopolymer solution can be cast about a support member and the solution freeze-dried to form a foam that has the shape of the mold and/or support member. For example, to model or replace a blood vessel, a tubular biopolymer foam construct can be created by placing the foam solution into a mold that includes a central support. The foam solution is then freeze-dried to have the desired shape. The foam is often further processed to increase the density of the foam. Unfortunately, the resultant biopolymer construct often strongly adheres to the support. Pulling, tugging or twisting the foam to remove it from the mandrel often damages the foam, rendering it less useful, or even totally useless, for in vivo or in vitro use.
Similar considerations apply to the removal of biopolymer constructs that are formed by winding, braiding or otherwise forming biopolymer fibers about a support structure.
Accordingly, there exists a need in the art for improved methods and apparatus for removing biopolymer constructs from support or shaping members. In particular, an object of the invention is to provide methods and apparatus that aid or assist the removal of the biopolymer material from the support.
The invention will next be described in connection with certain preferred embodiments. However, it should be clear that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. For example, various methods and systems employing various system structural components that utilize the preferred practice of the invention can be employed to facilitate removal or separation of a biopolymer construct from the support about which it is cast.